Detachable locking means for hypodermic syringe needles



Nov. 5, 1935. L. EISELE 2,020,111

DETACHABLE LOCKING MEANS FOR HYPODERMIC SYRINGE NEEDLES Filed June 16, 1934 Patented Nov. 5, 1935 "PATENT OFFICE DETACHABLE LOCKING MEANS FOR HYPO- DERMIC SYRINGE NEEDLES Logan Eisele, Nashville, Tenn. Application June 16, 1934. Serial No. 730,975

4 Claims.

My invention relates to improvements in hypodermic syringes, and particularly to means for detachably locking needles to the barrels of the syringes.

The principal general object of the present invention is to provide quick and effective means for detachably locking needles to the barrels of syringes, said means embodying a construction and arrangement of elements which can be easily produced, assembled and operated.

Another important object of the invention is to provide locking means embodying the foregoing features operable during assembly of the needle and barrel to firmly lock the needle to the barrel without placing any strain or stress on the tip of the barrel, which is highly desirable in the case of. glass barrels and tips.

The foregoing and other objects and advantages of the invention will become more apparent and will be pointed out during the course of the following detailed description of the accompanying drawing, in which Fig. 1 is a plan view of an assembled syringe, needle and the means locking the same together;

Fig. 2' is a side elevation of the parts shown in Fig.

Fig. 3 is an enlarged exploded perspective view of the needle lockingmeams and a portion of the barrel;

Fig. 4 is an enlarged sectional view taken on the line 44 of Fig. 2;

Fig. 5 is a view similar to Fig. 3 showing a modification in the locking means; and

Fig. 6 is a fragmentary enlarged side elevation of the parts shown in Fig. 5 in a position similar. to that of the locking-means in Fig. 2.

Referring to Figs. 1A, the letter B indicates generally the barrel of the syringe into which the fluid is drawn and from which it is expelled as usual by the plunger P. The barrel is provided with a reduced tip T which receives the hub of. the needle N, it being understood that as usual the tip, hub, and needle have communicating bores through which the fluid isdrawn into the barrel and expelled therefrom according to' the movement of the plunger.

As shown very clearly in the enlarged view of Fig. 3, the tip T is provided with an annular lateral flange or projection I spaced from the end 8 of the barrel B, and providing in conjunction therewith, a groove or channel 9 (to which the reference character is applied in Figs. 1 and 4). As will become more apparent hereinafter, it is not absolutely necessary to have the projection I continuous all the way around the tip T,

because separated projections could also be provided to serve the same purpose as the continuous flange or projection l; A metal strip is curved or bent or looped as at It! around the groove or channel 9 and is seated in the groove or channel 5 between the end 8 of the barrel and the inner face of the flange or projection I, so that the loop has no appreciable longitudinal. movement relative to the tip. The metal is then bent as at II and. extended substantially parallel with the 10 tip T to form an arm I2, the outer end I3 of which is bent in toward the tip T and spaced therefrom a distance less than the space between the arm I2 and the tip T.

It is not necessary to provide against relative 5 rotative movement between the loop I!) and the tip T, and, in fact, I deem it preferable to provide a frictional fit which allows such relative movement for a reason hereinafter pointed out. The needle may be provided with a finger grip forma- 20 tion I4 on the hub, and the shank I5 of the hub is providedwith a bore I6 which receives the tip T. The outer end of the shank I5 is formed with one or more cam formations, designated generally by the numeral I1, separated by a groove 01' 5 grooves I8. Face or edge I9 of the cam formation I I is'curved from adjacent the end of the hub and the groove I8 upwardly or outwardly. In the embodiment of the invention shown in Figs. 1-4, there are two cam formations H, but, of course, one would sufiice for the purposes of the invention, and there may even be more than two such formations for convenience in applying the needle to the tip and locking the parts together.

To assemble the needle and syringe barrel and lock the same together, the barrel is held with one hand and the needle in the other hand with the fingers preferably gripping the part I4. They are approached in substantially the relative position shown in Fig. 3, so that the end I3 of the 40 arm I2 will move along a'groove I8, and as soon as the end I3 has passed the lower end of the cam face I9, the needle is rotated so that the end I3 engages the face I9 drawing the parts tightly together during such rotative movement and preventing separation of the needle and barrel until it is desired to separate them. The separation is obviously accomplished by turning the needle reversely to the direction previously mentioned when looking the parts until the end I3 is in alinement with the groove I8, which permits the needle to be moved ofi of the tip.

As previously mentioned herein, it is not necessary to have the looped end rigidly secured within or to the surface of channel 9, as I deem it preferable to provide for relative rotative movement between the loop I and tip. Of course it is preferable to have a frictional fit between the loop l0 and the groove 9, such that the frictional engagement will prevent the arm I2 from swinging freely as the parts are brought together. A good frictional engagement is sufficient to facilitate the relative positioning and interlocking of the parts,

while the permitted relative rotative movement.

between the loop HI and groove 9 prevents imparting a stress or strain on the tips T, during the interlocking of the parts.

In Figs. and 6, I have shown a modificatio of the invention, wherein the primed numerals and letters designate the same parts as in Figs. 1-4, and wherein the metal strip is made the same with the exception of the locking end of the arm l2. In this modificationv of theinvention, the end of the arm l2, which corresponds.

in location to the end l3 of the arm I2, is formed with a cam face 20. The outer end of the shank [5' of the hub of the needle is provided with a flange 2| instead of the cam formation or formations IT. The flange 2| may be provided with grooves I8, at opposite sides thereof, through which the end 20 of the arm l2 may pass as the needle hub is moved on to the, tip T. When the end 20 has passed through any one of the grooves l8 beyond the inner face thereof and into the channel on the shank l5 between thegrip l4 and flange 2|, the needle and/or the barrelmay be rotated to bring the cam face of the end 20 against the substantially straight edge of the flange 2|, as shown in Fig. 6, to draw and hold the parts together.

From the foregoing, it should be obvious that this invention provides a simple arrangement for interlocking a needle and syringe barrel, and wherein the cooperating parts are easily made, assembled, and operated without placing a stress or strain on the glass tip during assembly. Although I have spoken of the tip T as being of glass, I wish it to be understood that the invention may be applied to other types of syringes than those made of glass, but for the reasons above given the invention is particularly adapted and useful in connection with glass syringes.

I claim:

1. In a hypodermic syringe including a barrel provided with a tip and a needlerprovided with a hub having a bore to receive the tip, a flange on the tip spaced from the end of the barrel and providing in conjunction therewith an annular channel around the tip, a metallic strip curved at one end around the tip within said channel whereby it is retained on the tip, said strip being bent along the tip in spaced relation thereto toward the end of the tip and having its outer end bent inwardly toward the tip, a flange on the end of the hub of the needle having its inner edge curved to form a cam surface and terminating at one end in a groove to receive said bent in end of the metallic strip, whereby when the tip enters the bore of the needle said bent in end may enter said groove and pass therealong after which when the tip and barrel are rotated relative to each other said bent in end of the strip engages said curved edge of the flange on the hub to draw the needle and barrel tightly together and to prevent separation thereof by longitudinal movement. 5 2. The structure of claim 1 wherein the portion of the strip which is coiled about the tip has frictional engagement therewith permitting relative movement between said portion and tip during the relative rotative movement between 10 the needle and barrel to avoid a twisting stress on the tip as the parts are drawn together.

3. In a hypodermic syringe including a barrel provided with a tip, and a needle provided with a hub having a bore to receive the tip, a pro- .1 jection on the tip spaced from the end of the barrel, a locking element around the tip in the space between said projection and end of the barrel, an arm on said element extending toward the end of the tip, a part on the end of the arm extending in toward the tip, a flange on the end of the hub of the needle, and a groove in said flange to receive said part and along which said part passes as the tip moves into the bore to position said part beyond the inner edge of said flange so that the needle and barrel may then be rotated relative to each other to position said part behind said inner edge with said arm extending across the flange to hold the needle on the tip against longitudinal movement, the portion of said locking element around the tip and in the space between said projection and end of the barrel being secured to the tip by frictional engagement permitting relative movement between its portion around said tip and the tip when the needle and tip are rotated relative to each other to avoid placing a twisting stress on said tip during said relative rotational movement.

4. In a hypodermic syringe including a barrel provided with the tip and a needle provided with a hub having a bore to receive the tip, a projection on the tip spaced from the end of the barrel,

a metallic strip curved at one end around the tip in the space between said projection and end of the barrel whereby the strip is retained on the tip, the portion of the strip which is curved around the tip in said space having frictional engagement with the tip permitting relative movement between said portion and tip to avoid a twisting stress on the tip, said strip being bent 5 along the tip in spaced relation thereto toward the end of the tip and havingv its outer end bent inwardly toward the tip, a flange on the end of the hub of the needle having its inner edge curved to form a cam surface and terminating at one end in a groove to receive 'said bent in end of the metallic strip, whereby when the tip enters the bore of the needle said bent in end may enter said groove and pass therealong after which when the tip and barrel are rotated relative to each other said bent in end of the strip engages said curved edge of the flange on the hub to draw the needle and barrel tightly together and to prevent separation thereof by longitudinal movement.

LOGAN EISELE. 

